It's the cycles that forum (and other) sites go through. The new trends of social networking lend themselves to forums just as well if you can integrate things smoothly.
Some coders that do it for a living have gone towards Wordpress or other forum software and it is where they can make money for themselves and their families. Can't fault them for that.
Personally, I run sites on both vBulletin and xenForo for different reasons.
You shouldn't put your eggs all in one basket, right